Generally, a heat-exchanging medium condensing device, such as a layered heat exchanger, is known being used for a cooling cycle for automobiles. This heat exchanger has a receiver tank connected thereto in order to prevent the cooling performance from being degraded.
This receiver tank is a device for separating a heat-exchanging medium, which is heat-exchanged with outside air by the heat exchanger to become a state of two phases of gas and liquid, into gas and liquid phases and returning only the heat-exchanging medium in a single phase of liquid so to be circulated through a cooling cycle. Thus, since the receiver tank is connected, the heat-exchanging medium is separated into gas and liquid by the receiver tank so as to become the heat-exchanging medium in only a single liquid-phase without containing a gas medium.
And, the receiver tank is determined to have a predetermined inside volume so that a sufficient amount of liquefied refrigerant can be stored therein.
Accordingly, the receiver tank can secure a stable circulating amount of the refrigerant and prevent the cooling performance from being degraded regardless of any changes in operation settings caused by outside environmental conditions, users or the like.
Besides, the receiver tank is provided with a filter, a desiccant and the like to remove foreign substances and water contained in the medium by their functions, thereby circulating the heat-exchanging medium in a clean state.
Conventionally, this type of condenser for the cooling cycle has the receiver tank integrally attached to the header pipe as shown in, for example, Japanese Patent Laid-Open Publications No. Hei 2-267478 and No. Hei 4-320771.
And, there is also disclosed a condenser and the like which has the header pipe configured to have inner and outer double tubes, the heat-exchanging medium flows into one of the tubes and the cooling water flows into the other so to simultaneously provide the function of the header pipe and that of the receiver tank as described in Japanese Utility Model Laid-Open Publication No. Hei 5-46511.
But, there was a disadvantage that when a separate receiver tank is mounted on the header pipe of the heat exchanger, a ventilation area of the heat exchanger was decreased due to the receiver tank, lowering the performance of the heat exchanger.
Specifically, such receiver tanks as described above retain a filter, a desiccant and the like therein in order to separate the heat-exchanging medium which consists of the two phases of gas and liquid into these two phases, and need a certain level of volume.
And these receiver tanks are generally mounted on the side of an ordinary header tank. But, since the heat exchanger mounted on a vehicle has a limited maximum front area due to its mounting space and must be made small for making a space for the receiver tank, it has a disadvantage that the heat-exchange performance is lowered.
Where the header pipe has a double tube structure so to have the function of the receiver tank, the cooling effect may be enhanced by mounting a cooling fan within the header pipe, and a volume therefor is required correspondingly. Therefore, there are disadvantages that the volume is increased inevitably, and not only the front area of the heat exchanger is limited in the same way as described above, but also the inside volume is limited.
Besides, a conventional liquid receiver is configured to retain a desiccant and the like within a single tube. The heat-exchanging medium in two phases of gas and liquid flows into the liquid receiver and separated into two phases of a gas medium and a liquid medium by the desiccant and the like within the liquid receiver. Therefore, there is a possibility that the separated mediums are re-mixed into the medium of two phases of gas and liquid depending on environmental conditions and the like.
Specifically, a passage of the medium formed within the liquid receiver has a simple and linear one-way form, and the desiccant or the like is disposed at midways in the passage. Therefore, there is a disadvantage that the performance of separating gas-liquid becomes insufficient.
In view of the disadvantages described above, it is an object of the present invention to provide a structure of the receiver tank by which only the liquid medium can be flowed again without using a special sealing member or the like after separating the heat-exchanging medium into the liquid medium and the gas medium so to be able to improve the cooling effect and which can be mounted on the header pipe at any angle.